The present invention concerns an anchoring system using a harpoon and a grid for securing a vertical take-off and landing aircraft to a platform and more particularly, to, the head of the harpoon in such a system, as well as the harpoons provided with this head.
Harpoon and grid securing systems are of great significance for helicopters that must land on or take off from moving areas, such as ship decks, oil platforms, and even solid ground in zones exposed to violent winds. The significance of these systems is that the helicopter is anchored to a platform, and therefore stabilized, without delay and in an automatic manner. Similarly, the helicopter is released without external human assistance at the last moment before take-off. These systems comprise a grid mounted in the landing/take-off platform, defining cells with open bottoms, delimited by bridges or isthmuses. The harpoon is mounted underneath the helicopter and substantially comprises a retractable arm and, at the end of the arm, a head for catching in the grid.
In the known forms, if the grid is satisfactory overall, improvements can still be made with respect to the harpoons, which are generally heavy, bulky and complex systems, with respect both to their structure and their operation. Since the mechanical, hydraulic and electrical interfaces are large, the harpoons cannot be simply installed on a helicopter if this was not initially intended by the manufacturer.
The head includes a clamp, the jaws of which close around an isthmus between two cells. Apart from the fact that it is quite bulky, it is, in itself, relatively complex, using hydraulic and electrical means for its operation. Furthermore, on catching, the retention force that it transmits onto the grid, if significant, can be damaging to the grid since it is applied to a single isthmus.